1. Field of the Invention
The present invention relates to thermoplastic resin pressed sheet-like materials showing superior mechanical properties, in particular toughness and high-impact properties, as well as good appearance.
2. Description of the Prior Art
Recently, thermoplastic resin sheet-like materials themselves or the products obtained by vacuum forming, pressure forming, stamping forming and the like thereof are widely used in various kinds of vessel, parts of cars, parts of electric instruments and the like. It is, however, well known that the addition of flaky fillers to thermoplastic resin leads to the remarkable improvement in strength and elasticity for the field, wherein high strength and elasticity are required and anisotropism is undesirable, of the above described fields. In the case when still higher strength and modulus of elasticity are desired, as disclosed in for example Japanese Patent Application Laid-Open No. 161667/1979, the desired object can be achieved by pressing the compound at temperatures sufficiently higher than the melting point thereof to orientate flaky fillers. It is, however, the greatest disadvantage for the cases when flaky fillers are added to thermoplastic resin as reinforcing fillers that the compound becomes brittle, that is to say it shows low toughness and reduced impact resistance, in particular reduced Izod impact strength. Besides, this tendency becomes more remarkable with the orientation of flaky fillers. On the other hand, as disclosed in Japanese Patent Application Laid-Open No. 27203/1980, the transparency of thermoplastic resin sheet-like materials can be improved by stretching or pressing them at temperatures lower than the melting point of thermoplastic resin; and as disclosed in U.S. Pat. No. 4,282,277, the toughness of resins can be improved by pressing them at temperatures lower than the melting point of said resins. But, in the cases when flaky fillers are added to the compound, the stretched or pressed products show whitening owing to the phenomenon in which the superficial part thereof is stripped by the thickness of the same degree as that of said flaky fillers; the improvement of physical properties is unsatisfactory; or the dimensional resistance in an atmosphere of high temperatures is low whereby only the products having no practical use are obtained.